/*
 * Copyright 2002-2020 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.springframework.security.oauth2.client.jackson2;

import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;

import java.util.Map;
import java.util.Set;

/**
 * Utility class for {@code JsonNode}.
 *
 * @author Joe Grandja
 * @since 5.3
 */
abstract class JsonNodeUtils {
	static final TypeReference<Set<String>> SET_TYPE_REFERENCE = new TypeReference<Set<String>>() {};
	static final TypeReference<Map<String, Object>> MAP_TYPE_REFERENCE = new TypeReference<Map<String, Object>>() {};


	static String findStringValue(JsonNode jsonNode, String fieldName) {
		if (jsonNode == null) {
			return null;
		}
		JsonNode nodeValue = jsonNode.findValue(fieldName);
		if (nodeValue != null && nodeValue.isTextual()) {
			return nodeValue.asText();
		}
		return null;
	}

	static <T> T findValue(JsonNode jsonNode, String fieldName, TypeReference<T> valueTypeReference, ObjectMapper mapper) {
		if (jsonNode == null) {
			return null;
		}
		JsonNode nodeValue = jsonNode.findValue(fieldName);
		if (nodeValue != null && nodeValue.isContainerNode()) {
			return (T) mapper.convertValue(nodeValue, valueTypeReference);
		}
		return null;
	}

	static JsonNode findObjectNode(JsonNode jsonNode, String fieldName) {
		if (jsonNode == null) {
			return null;
		}
		JsonNode nodeValue = jsonNode.findValue(fieldName);
		if (nodeValue != null && nodeValue.isObject()) {
			return nodeValue;
		}
		return null;
	}
}
